Browsers traditionally provide basic privacy protections usually focused around cookie management, but newer browsers are also supporting the Do Not Track (DNT) header request as an alternate method of indicating user preferences. Until the industry fully adopts DNT, a temporary solution could be to integrate DNT recognition mechanisms into existing cookie-based systems.

Cookie-Based Opt-out Tools

Cookie-based opt-out tools use cookies to indicate to tracking companies’ opt-out mechanisms that a user wishes to be opted-out of behavioral advertising. While this method of control is relatively easy to implement, it places the burden of control on the user (who may encounter large numbers of tracking domains), and even with a centralized opt-out database this can prove cumbersome. This method also relies on cookies to signal user preferences to the tracking companies – therefore deleting cookies (a common consumer approach for controlling privacy) also deletes the opt-out preferences.

There are a number of providers of cookie-based opt-out services which aggregate opt-outs for multiple tracking companies (including the TRUSTe preference manager). Unfortunately it’s unlikely that consumers can digest a large list of networks and data providers and select a few from which to opt-out. The complexity of the ad ecosystem therefore renders this level of transparency slightly less useful.

‘Do Not Track’ Header

The ‘Do Not Track’ header is a browser feature that appends a header to http requests that expresses a user’s preference not to be tracked, placing the burden for compliance on trackers (currently implemented in newer versions of Firefox and IE). This creates the possibility for the header to provide much broader-based protection against tracking than the other mechanisms if tracking companies abide by it.

A strong advantage of the DNT header is that it makes it clear and simple for companies to comply with the law – and to send a straightforward signal to users that their company is compliant and trustworthy. Plus, it makes it easy for consumers to take a stance and state a clear preference regarding tracking.

An Integrated Solution

The current industry standard makes use of a script-based in-ad icon, from which consumers who are interested in stating ad preferences can follow a link to a cookie-based opt-out tool. The EU (which stresses an opt-in model) and US (which takes the opposite stance with opt-out) are also converging, and as they do it is becoming more obvious that future systems need to be simply ‘preference based’, not necessarily just opt-in or opt-out.

While in-ad tags are a great transparency mechanism, the cookie-based service which it supports is only a moderately useful choice mechanism. Conversely DNT settings provide consumers a decent global choice mechanism, but offer little in the way of transparency. There needs to be a linkage between the in-ad tags and browser-based DNT settings. Cookie-based systems, the current industry standard, are not going away anytime soon, but an ideal solution should integrate DNT standards into existing cookie-based systems as well as any future preference-stating systems as the industry evolves.

TRUSTe has developed a DNT-integrated ad tag solution – one that is capable of acknowledging a user’s DNT preference but can leverage the transparency afforded by the in-ad icon. The ad tag script is capable of acknowledging a user’s DNT browser preference and can leverage the transparency afforded by the in-ad ‘AdChoices’ icon to reflect this preference. If DNT is set, the ad tag temporarily displays an altered state icon acknowledging the preference. Since it can also be assumed that a user who has stated a ‘Do Not Track’ preference does not wanted to be targeted, the system can automatically record the user’s preference by triggering opt-outs for all tracking entities associated with the ad tag, similar to the action the user could take by following the link to the cookie-based preference manager. This can serve as an interim bridge between DNT and cookie-based preference systems until DNT gains mainstream adoption, combining the global choice of DNT with the transparency of the current industry ad choices icon.